(adsbygoogle = window.adsbygoogle || []).push({}); [SOLVED] Vector Problem

I hope someone can help me. I am so tired of trying to figure this out.

A man pushing a mop across a floor causes the map to undergo two displacements. The first has a magnitude of 110 cm and makes an angle of 110° with the positive x axis. The resultant displacement has a magnitude of 240 cm and is directed at an angle of 25.0° to the positive x axis. Find the magnitude and direction of the second displacement. Find the angle with respect to the positive x axis.

I started by measuring 110 degrees and drew my vector starting at the origin (origin is point A). The end of this first vector is point C. Then, starting at point A again (since this vector is the resultant vector) I measured an angle of 155 degrees (180-25=155) and drew my vector, the end of which is labeled point B. I then drew the connecting vector, vector BC.

Now, I drew a line straight down from point B to the x-axis. This point is D. I need to find the x and y components of this right triangle, triangle ABD. By using the angle of 155 degrees I can say cos155=x divided by 240. This equals -217.5139. To find y, I can say sin155=y divided by 240. This is 101.4284.

Now, I drew a line from point C straight over to the y-axis. This will be point E. I need to find the components of triangle ACE. So, cos110=x divided by 110. This is -37.6222. And sin110=y divided by 110. This is 103.3662.

This is the point where I'm not sure what to do. Since the unknown vector, BC, is a hypotenuse of a third right triangle, I just don't know what to do next. I thought I could take the difference of the x values and y values I found, then use the Pythagorean theorem to get vector BC, but I get the wrong answer. (I keep getting vector BC equals 180.)

I hope I was able to explain what I did without confusing anyone. I would be ever so grateful for some help.

**Physics Forums | Science Articles, Homework Help, Discussion**

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Homework Help: Vector Problem

**Physics Forums | Science Articles, Homework Help, Discussion**